Chris Cox has an article in FrontPage Magazine that outlines the issue well:
Many fully-automatic firearms can fire 10 rounds in a second, which theoretically would work out to 600 rounds per minute, but they cannot be reloaded fast enough to achieve anything near that rate in reality. But we are not talking about fully-automatic firearmsâ€”we’re talking about semi-automatics, and the difference between them need not be explained here.
I think that’s a good way to frame that issue.Â Machine guns aren’t these scary objects that spew death and hellfire from their barrels, but that’s not what we’re talking about either.Â This changes the subject, without throwing machine guns under the bus.Â Is NRA deliberately being more careful about this?Â I hope so.
NRA members who own AR-15s and other so-called “assault weapons,” you are not alone. There are nearly two million AR-15s in our country, the same number of M1s, the same number of M1 Carbines, and many more Mini-14s, semi-automatic shotguns, pump-action shotguns, and all the other guns the anti-gunner want to call “assault weapon.” Countless millions of American own handguns that use magazines of over 10 rounds.
I would say that passes the Heller “common use” test pretty soundly.